Heat vegetable oil in a large saucepan over medium heat. Stir in curry paste; cook and stir for about 2-3 minutes (make sure your fan is blowing.. or your house is going to smell!). Add 1 can coconut milk and stir until well blended. Add ginger, cilantro, sugar, fish sauce, lime juice, and Worcestershire, bring to a boil. Add onion and chicken then reduce to a simmer. When chicken is white and cooked through (about 5 min or so) add remaining ingredients (except for the rice) and stir until everything is well mixed. Cover and simmer for about 15 minutes--until potatoes aren't crunchy in the middle. Serve hot over Jasmine rice.